Book excerpt: Which elements do the Arab Spring, the Indignados and Occupy Wall Street have in common? How do they differ? What do they share with social movements of the past? This book discusses the recent wave of global mobilisations from an unusual angle, explaining what aspects of protests spread from one country to another, how this happened, and why diffusion occurred in certain contexts but not in others. In doing this, the book casts light on the more general mechanisms of protest diffusion in contemporary societies, explaining how mobilisations travel from one country to another and, also, from past to present times. Bridging different fields of the social sciences, and covering a broad range of empirical cases, this book develops new theoretical perspectives.